The structure and function of the brain
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The document summarizes the structure and function of the major parts of the brain. It describes the cerebral cortex as having sensory, motor, and association areas. It then discusses the four main lobes of the brain - the frontal, parietal, temporal, and occipital lobes - and describes the primary and association areas within each lobe. The primary areas are responsible for basic sensory and motor functions, while the association areas integrate information for higher cognitive processes.
The structure and function of the brain
- 1. Lesson 5 The Structure and Function of the Brain Sunday, 29 January 2012
- 2. Lesson 4: The Neuron Exam Question a) Label the diagram below (1 mark) b) Describe how a neuron transmits information. (3 marks) Sunday, 29 January 2012
- 3. b) a) A neuron transmits 1. Synaptic Knob information by creating an 2. Myelin Sheath action potential. 3. Axon When a neuron is 4. Node of Ranvier stimulated, channels in its 5. Soma (cell body) membrane open, briefly 6. Dendrites allowing positively charged 7. Nucleus sodium ions to rush in, this creates a change in electrical activity leading to an action potential. Sunday, 29 January 2012
- 4. Lobes of the Brain Sunday, 29 January 2012
- 5. Cerebral Cortex The cerebral cortex is the thin (3-5 mm thick) convoluted (folded) outer layer of the brain. The value of the folding is that it enables a greater surface area of cerebral cortex to be contained within the skull; this gives a greater volume and enables the cerebral cortex to contain more neurons and more blood-vessels to get more oxygen and glucose (for energy) to this most fuel-hungry part of the body. There are three main types of functional areas in the cerebral cortex: 1. the sensory areas which receive information provided by the various senses (especially touch, vision, and hearing); 2. The motor cortex which sends information to muscles so they can create bodily movements 3. The association areas which integrate sensory and motor information and are involved with information processing activities such as language and speech, learning, memory, thinking and problem solving Sunday, 29 January 2012
- 6. Frontal Lobe The frontal lobes are the largest lobes and occur on the top front halves of the cerebral hemispheres. The primary motor cortex is at the back of the frontal lobes. It runs across the top of the brain from left to right. It is divided by the longitudinal fissure that separates the two hemispheres. Specific areas of the motor cortex are responsible for the movement of particular body parts. · Right Controls Left/Left Controls Right · Top Controls Bottom/Bottom Controls Top Sunday, 29 January 2012
- 7. Motor homunculus— represents the body parts in terms of the relative size of the area each of body part occupies along the primary motor cortex. Sunday, 29 January 2012
- 8. Association Areas in Frontal Lobe Broca’s Area: the “Speech Production Centre” is part of the association cortex. It is located in the left frontal lobe and is involved with the production of clear, fluent speech. Broca’s area helps us with the structure of sentences and parts of speech such as adjectives, prepositions and conjunctions. Broca’s area is involved with analysing the grammatical structure of sentences that we hear as well as those that we speak. Other association cortex in the frontal lobes is involved in Reasoning Planning Thinking Sunday, 29 January 2012
- 9. Parietal Lobe The parietal lobes are located on the top central part of the brain. Primary Areas in the Parietal Lobes – The Primary Somatosensory Cortex The primary somatosensory cortex is at the rear of the central fissure, immediately opposite the primary motor cortex. The primary somatosensory cortex registers the sense of touch, by receiving information about pressure, pain, temperature, muscle movement and position from sensory receptors around the body It is divided by the longitudinal fissure that separates the two hemispheres. Specific areas of the primary somatosensory cortex receive sensations from particular parts of the body. · Right Receives From Left/Left Receives From Right · Top Receives From Bottom/Bottom Receives From Top Sunday, 29 January 2012
- 10. Sensory homunculus—Similar to motor homunculus but it tells the brain how much power is needed for sensory perception of different body parts. Sunday, 29 January 2012
- 11. Association Areas in Parietal Lobe The association cortex of the parietal lobes is important in Integrating visual information Monitoring the body’s position in space Determining where objects are located in space. Sunday, 29 January 2012
- 12. Temporal Lobe Primary Area in the Temporal Lobes – The Primary Auditory Cortex Auditory – sound – information is sent to the primary auditory cortex, located slightly above and in front of the ears. Sunday, 29 January 2012
- 13. Association Areas in Temporal Lobe Wernicke’s area - the “Speech Reception Centre” is part of the association cortex. It is located in the left temporal lobe and is involved with the reception and comprehension of speech. * Stores the receptor codes for language or enables comprehension of speech/language * Enables interpretation of the written word * Is used for locating words from memory to express a particular meaning * Is used for creating meaningful and/or grammatically correct speech Other association cortex of the temporal lobes is important in Memory - the ability to remember faces Storing of episodic memories such as our first day at school or a particular holiday Recognition of objects Sunday, 29 January 2012
- 14. Occipital Lobe Primary Area in the Occipital Lobes – The Primary Visual Cortex Visual information from the eyes is sent to the Primary Visual Cortex in the occipital lobe at the back of each cerebral hemisphere. Sunday, 29 January 2012
- 15. Association Areas in Occipital Lobe The association cortex of the occipital lobes is important in Selection, organisation and integration of features of visual stimuli. Sunday, 29 January 2012
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